Tunnel casing rings usually comprise several individual casing segments or ring segments, and the casing rings, when positioned alongside each other, form an inner interior casing, duct, tube or similar protective circular structure. This structure lines the tunnel wall at a spacing therefrom in which concrete can be emplaced. The rings or casing sections are removed when the concrete has been set and the casing is no longer necessary.
An apparatus for installing and removing such rings can include a tubular support bridge structure and a transport carriage. The transport carriage is guided at the support bridge structure and can move or travel in longitudinal directions along the support bridge structure. The apparatus also can include a carriage or drive support ring on which are mounted the supporting framework or undercarriage for an operator station and associated drive means.
Furthermore, a segment support ring is arranged ahead of the drive support ring and parallel with respect to the latter. The segment support ring carries radial adjustment manipulator assemblies for the control of casing segments of a respective casing ring.
Two additional support rings can be provided of which the first one, also referred to as first intermediate support ring, is mounted between the carriage support ring and the segment support ring. The second support ring is arranged concentrically within the first support ring in such a way that it can turn or rotate in the first intermediate support ring.
The apparatus furthermore includes several piston-cylinder assemblies for actuating the first support ring, for moving the second support ring, and for inclining the segment support ring.
An apparatus of this type is described in German Utility Model (Gebrauchsmuster) No. 82 02 276. The inclining piston-cylinder assemblies in the apparatus of the German utility model are also arranged between the carriage support ring and the first intermediate support ring. The further support ring is identical with the segment support ring. Together with the first intermediate support ring, the segment support ring is of a construction equivalent to that of a sliding bearing, whereby the outer ring is provided by the segment support ring, and the inner ring is provided by the first intermediate support ring.
A disadvantage of this system is that the adjustability is limited and, control movements require complex hydraulic controls in order to alleviate kinematic incompatibilities.